Lignocellulosic biomass is viewed as an abundant renewable resource for fuels and chemicals due to the presence of sugars in the cell walls of plants. More than 50% of the organic carbon on the earth's surface is contained in plants. This lignocellulosic biomass is comprised of hemicelluloses, cellulose and smaller portions of lignin and protein. Cellulose is a polymer comprised mostly of condensation polymerized glucose and hemicellulose is a precursor to pentose sugars, mostly xylose. These sugars can easily be converted into fuels and valuable components, provided they can be liberated from the cell walls and polymers that contain them. However, plant cell walls have evolved considerable resistance to microbial, mechanical or chemical breakdown to yield component sugars. A number of approaches to overcome this recalcitrance have been performed and the breakdown of these polymers into sugars, saccharification, has a long history.
US2014/0018555 describes a process for producing furfural from lignocellulose-comprising biomass is disclosed. The biomass is slurried in water and optionally an acid, subjected to hydrolysis, and then subjected to a solid/liquid separation to yield at least an aqueous fraction comprising C5 and C6 sugars and a solid fraction comprising cellulose and lignin. Furfural is obtained by adding an organic solvent to the aqueous fraction, heating at 120-220° C. for a sufficient time to form furfural, cooling, and separating an organic phase comprising at least part of the furfural from an aqueous phase. As suitable organic solvents water miscible and water immiscible organic solvents are suggested.
The process of US2014/0018555 requires a continuous supply of organic solvent, which is undesired when the process is operated at remote locations.
U.S. Pat. No. 8,168,807 describes a process for a one stage preparation of 2-methyltetrahydrofuran from furfural over two catalyst in a structured bed. The 2-methyltetrahydrofuran is prepared by one-stage hydrogenation of furfural with a hydrogen-comprising gas in the presence of a structured bed of at least one copper catalyst and at least one catalyst which comprises at least one noble metal from groups 8, 9 and/or 10 of the periodic table of the elements applied on a support material. There is a need for improving the efficiency of the process by reducing the demand for organic solvent to be provided to the process.